Eight senators have called out the Department of Homeland Security (DHS) about numerous stops and searches of law-abiding pilots on domestic flights that never leave U.S. airspace.

In a letter to DHS Acting Secretary Rand Beers, the lawmakers, all members of the Senate General Aviation Caucus, demanded that the DHS provide records of all stops of GA flights since 2009, including explanations of the “reasonable suspicion” that led to each stop by officers from Customs and Border Protection (CBP) and the “probable cause” that resulted in a search. The DHS is the parent agency of CBP.

“Recent reports and first-hand accounts from pilots indicate a significant rise in the number of unwarranted stops and searches of U.S. general aviation aircraft that did not cross the U.S. border by the Air and Marine Division of the [CBP] agency,” the solons wrote.

“While we appreciate law enforcement efforts to protect our national interests and combat illegal activity, the abrupt increase in the number of stops and searches of personnel aboard general aviation aircraft raises concerns that CBP may be violating our citizens’ Fourth Amendment rights,” they said.

Some House members also have signaled their concern with what appear to be warrantless searches. During a September 9 meeting, AOPA president and CEO Mark Baker and Rep. Sam Graves (R-Mo.), co-chairman of the House General Aviation Caucus, discussed the importance of protecting law-abiding pilots from unreasonable search and seizure.

Graves, a GA pilot, sent a letter to the inspectors general at the Transportation Department and DHS asking for an investigation into CBP’s actions. In his letter, Graves noted that in more than 40 reported cases of stops and searches, no evidence of criminal activity has been found, raising the question of whether the searches are reasonable.

In a response to the letter, Thomas Winkowski, acting commissioner of CBP, cited regulations allowing any federal agent to check pilot and aircraft documents as the basis for stopping, searching and sometimes detaining law-abiding pilots on domestic flights.

AOPA has filed numerous Freedom of Information Act requests in an attempt to determine under what authority the CBP is stopping purely domestic flights. The association brought the issue to the attention of lawmakers after its requests were ignored or received inadequate responses.

“Without a reasonable suspicion of illegal activity, a warrant or probable cause, law enforcement has no business stopping aircraft in the first place, let alone searching and possibly detaining law-abiding pilots,” said AOPA general counsel Ken Mead, a former DOT inspector general. “We can’t afford to have law enforcement agencies that act outside the scope of their authority and then try to hide behind laws designed to protect our national security. They have to be accountable to the citizens they are supposed to serve and [the senators’ letter] is one way to help ensure that accountability.”